The collagen species in cartilage will be studied with the aim of determining their mode of biosynthesis and extracellular processing. The structure of biosynthetic intermediates and collagen molecules will be determined to establish the normal route for the elaboration of collagen into the extracellular matrix. The interaction between a chondrocyte adhesion factor chondronectin, and collagen will be investigated to determine the role of this interaction on cell attachment. Chondronectin will be purified and monoclonal antibodies will be used to determine its distribution in cells and in tissues. Collagen synthesis will be examined using metabolic labeling of cartilage cells and organ cultures. Comparison of metabolically labeled collagen with collagen obtained by extraction of tissues will be executed by peptide mapping. Chemical purification of chondronectin from relatively rich sources such as serum or synovial fluid will be achieved by a combination of biochemical techniques including ion exchange and affinity chromatography. The influence of collagen and of chondronectin on cellular properties will be studied by cell adhesion. The localization of chondronectin in cell cultures and its distribution in tissues will be established by immunofluorescence and immunoferritin electron microscopy. The long term objectives of this proposal are to determine (a) the extent of involvement of collagen in an extracellular cell surface-associated matrix and (b) the influence of collagen and chondronectin on cell behavior in order to understand the normal response of cells to the extracellular connective tissue matrix. Studies of the normal biosynthesis of collagen and the chondrocyte adhesion factor, chondronectin, and knowledge of the normal interactions between the cells and their environment will be extended to a study of abnormalities in connective tissue structure and function. Normal cell-cell and cell-matrix interactions are required in fracture repair and wound healing. This work will lead to a study of (a) the precise role of cellular environment in maintaining normal cell morphology and growth, (b) the changes which occur in connective tissue proteins during development and morphogenesis and (c) the abnormal growth properties of cells involved in tumorogenesis and metastases.